Racket stringing machine



Patented June 17, 1941 RACKET s'rnmolNoMiqiennvn' I I Edmundo IL-Serrano; stt'Li tllis Mlll I Application was 17, 1940; despairing l f '6 Claims. I (c1. 273573)] closed herein is of the general character disclosed in application for patent filed by.-E. H. Serrano,

oil-October 14, 1938, Serial N0.' 235,063,' which will merge into patent on January 23, 1940,- and be numbered 2,188,250, the invention disclosed in this application being particularly directed to improvements in the string tensioning means to be used with the machine as disclosed in the Serrano patentreferred to, l

With the above and other objects in viewthat will become apparent as the nature of the invention is better understood, the same consists in general of certain novel details of construction and combination of parts hereinafter more fully described, illustrated in the accompanying drawing and claimed a i p 1 In the accompanying drawing: 1 a v Figure-'1 is a vertical sectional view of a racket stringing machine constructed in accordance-with the present invention and illustrating the string-V tensioning devices, I v

Figure 2 is adetailed sectional view taken online 22 of Figure 1, showing the anti-friction mounting for the slidable stringing tension bar,

Figure 3 is a vertical sectionalview of the dash boarddevice for cushioning descending movements of-the weighted end of thestring tensioning treadle bar. I 1 A The frame-structure of the racket'stringing machine together with the carrying or supporting member for the'racket are only illustrated to provide supporting means for the string-tensioning device, the racket machine frame structure including a tubular standard or post Ii] rising from a'fioor-anchored base plate -I l, the upper end of the post iii supporting a head structure designated in general by the reference character-J2 and upon. which an elongated .plate 13 is piv-. otally supported adjacent one end thereof asat lgi ior pivotal or swingingmovements in a horizontal plane. A block |5.;rigid with the free swinging end of the plate l3 rises from said plate and carries an arm l6 provided at, its free end with a pair of gripping jaws ll for the support tion- ,With the block l and is held in adjusted positions by the set screwv2 I, the'other endof the;

barp2fi having an arm 22 rising therefrom'that carries clamp-ing jaws 23 forthesupport of. the

opposite side of the loop portion l8 ofthe racket i9. A horizontal stub shaft 24 projects laterally:

of the block [5 and has mounted thereonone end of anlelongated rod 25 extending parallel with the bar 20, the. rod 25 adjustably supporting a string clamp 26,:the clamp 26 mounted uponvthe rod25as shown-in Figure 1 being associatedwith; the strings extending longitudinally of the racket, frame .loop 13;": String clamps or grippers are to be engaged with-the strings that extend transversely of the racket frame loop andtoaccOm-J modate the appropriate-mounting of thest iing clamps, ablock 21 is adjustably secured to; the:

bar-29 andcarries'laterally directed horizontal stub shafts 28 upon which the clamps may be supported. 1 r v The string tensioning means includes devices supported on the post and cooperating with the head structure i2, the latter as shown in Figures 1 and 2 comprising a top plate 29'uponr which the plate I3 is pivotallymountedythe plate 29 carrying at each end'thereof a depending channel or U-shaped member '30 having side walls 3|; the free edges of whichabuttingly engage channel members 32 of U-shape that comprise upstanding side walls 33, the side walls 3| and 33 of the channel members and 32 being secured together by tie bolts 34. The lower channel mem-- bers 32 are seated in diametrically opposite notches provided in the upper end of the tubular post 10 and are suitably anchored therein. The

- assembled channel members 30 and 32 provide engaged with the racket string 42 as shown ,in

Figure l. The operating means for the slide rod 36 includes an elongated lever 43 mounted with in the tubular post l0 and having a link connection 44 intermediate its ends with the bracket,

of one ,endof the looped frame portionT ilfofa racket IS. A bar 20 has a keyed sliding-connecend of the. tubular post IO- and is-pivotally mounted intermediate its ends within said post upon the horizontal pin 50 carried by an upstanding bracket arm I. bar 41 extending through the slotted opening 48 carries a treadle plate 52 while the end'of th'e' treadle bar 41 extending thrOugh the slotted opening 49 is calibrated as at 53 and has weights 54 adjustably mounted thereon by' means of screws 55. An arm 56 is carried by and perpendicularly projects from the treadle bar 41 Within the tubular'post IOand' at a pointbetween the treadle 'b'ar pivot 53 and the slotted 1 opening 48","th'e upper end of the-arm 56carrying a'roller 51 "engaged with' 'the adj'a'cent side of the lever 43; a lea'f spring 58 having one end attached as at'59 to the' arin 51 intermediate the ends thereof has the other'end'thereo'f engaged with the sideof thelever 43 as at 60 oppo'sitethe' roller engagementst To 'cushion 1 the descending movement of the" weightede'nd o'f' thetreadle' bar 41 when-the treadlepIate 52is relieved of foot pressure, there is*provided=a dash-potdevlce comprising a fluid c'ylir'ider 6'I closed at its lower endand open at its-"upper end and pivotally supported intermediate its ends as at62" in apair ofupstanding lugs 6'3*'risin'g-from the base plate I I at opposite sides oft he opening 64"throughwhich the cylinder 6I extends. A tubular piston 65 is reciproca'bly mountedwit'hin the cylinder 6| and carries'a't its upper end 'a'pa'ir of lugs 66 to straddle the-treadle bar 41 with openings 61 in said lugs toaccom= mo'date the mounting of a pivot pin 68f A downwardlyopening spring-pressed valve'69- is carried by the bottom wall of the'piston 65 and said piston 65' has a pair of vertically spaced annulargroove's win the outerwall' thereof with openings 11 extending through the bottom walls of said' grooves to per'mit'the return of fluid to thecylinder 61 that passes upwardly between the piston and cylinder during descending" movemerits of the piston.

With the treadle bar in the'position illustrated in'"Figu're '1, it'isundersto'od that'the' operator of a the racket strln'gingn'iachinehas hisfooton the treadle-"plate 52" to hold the'weight'e'cl 'end' of the' tre'a'dle bar elevated. The string clamp 40 isthenengaged with'the racket string- 42 and'when the" treadle plate is relieved of foot pressure; the

weighted" end of the treadle 'bar' lowers; being cushioned by the dash pot construction, while the arm 5'6 carried by saidtreadlebar'with-the roller 51 engaged' with the lever 43' movesaid level onits' pivotal link' connection 44=with thetubular' post Ill to' causethe'" upper end-of the lever' 43't0 move the slide rod 36 that carries the string clamp 40. The weights 54 are ad-' justably' mollnted upon the calibrated end 53 ofthe treadle bar 41 toinipart the desire'd t'eng sio'n to the engaged racliet" string and after such' tension has" been placed'on'the string, the era-nip 2t"is*enga'ged with the string withinthe racketioo'p' I6 to hold the string section s'o te'n'siofied during" shifting movements" of the plate I73 for the t'ensioning or a secondor succeeding section- The end of the treadle of the string. when the treadle plate 32 has foot pressure applied thereto, the weighted end of the lever is elevated and the spring 58 carried by the arm 56 causes a reverse pivotal movement of the lever 43 and a corresponding reverse sliding movement of the rod 36 so that the clamp 40 carried by said rod 36 will again be positioned for proper engagement with a string section to be tensioned. The anti-friction hearing balls 31 permitan easy: sliding movement of;the-rod 36. The'bracket arm' 39 and string gripper 46 are adjustably mounted on the bar 20 so that the string gripper 40 can be placed the same distance from the racket frame loop I8 when the same is shi-fted with plate I3 for gripping the racket string" to assure an even tension being ifnpartedto' all'sections of the racket string.

Whilethereisherein shown and described the preferredembodiment of the invention, it is to b"under'stood that minor changes may be made in the details of-constr'uction, such as will fall withirithe scope' of the invention' as claimed.

I claim: I

1. In a racket stringingmachine, wherein a racket supportingrh'ead is mounted upon the upper'end'of atubular'post; string tensioning means including'a rod slidable transversely of the upper end'ofthe' post beneath the head, a string-gripper on one end of said rod, a substantially vertically disposed lever-pivoted between its upper and lower ehd=in-the tubular post to the side wall-thereof with theupper end of the lever .pivotally' attached to'sa'id slide' rod and aw'eighted treadle b'ar'extending transversely of the-lower end'of the post below the lowerend of'said'lever and operatively engaged-with thelower end of said lever.

2:- In a racket stringing machine, wherein a racket? supporting head is mounted upon the upper end of a tubular post; string tensioning means including: a' rod slidable transversely: of the up-- per end-"of the post: beneath the head, a string gripperon= one end, of said-rod, a substantially vertically disposedlever pivoted-between its upper; and lower ends in the tubular post to the sidewall thereof with the upper end of the lever pivotally attached to said slide rod and a weighted treadle bar extending transversely of the lower end ofthe-post;- below'the; lower end of said-lever andioperatively engaged with the lower end'of sai-d lever, achannel; guide at the upper end of the post through which the rodis slidable and anti-friction bearings in said guide for said rod.

3;;In a racket stringing machine, wherein a racket-supportingheadismounted upon the upper end of a tubular post, string tensioning means including a rod slidable transversely of the upper end-of the post beneath thehead, a string gripper on one end of said rod,=.a substantially vertically disposed lever pivoted between its upper and lower ends in-the tubularpost to-the side wall'thereof with the-upper endof the'le ve r pivotally" attached tosaid slide rod and a weighted treadle bar extending-transversely of; the lower end of the post below the lower end-of said lever and operatively engaged with the lower end of said lever, the connection between the itreadle bar and lever including an arm carried by'the treadle-bar and having a roller-at its free'end' engaged 'with' one side of raiclg etisi'ipporting head -is m'ollnted upon the up per e'nd of aftubul'ar post; string tension'in'g means including a rod: slidaible transversely of theupper end o'ith'e post beheath' the head, a string grip per on one end of said rod, .a substantially vertically disposed lever pivoted between its upper and lower ends in the tubular vpost to the side wall thereof with the upper end of the lever pivotally attached to said slide rod and a weighted treadle bar extending transversely of the lower end of the post below the lower end of said lever and operatively engaged with the lower end of said lever and a dash-pot construction associated with the treadle bar for cushioning descending movements of the weighted end thereof.

5. In a racket stringing machine, wherein a racket supporting head is mounted upon the upper end of a tubular post, string tensioning means including a rod slidable transversely of the upper end of the post beneath the head, a string gripper on one end of said rod, a substantially vertically disposed lever pivoted between its upper and lower ends in the tubular :post to the side wall thereof with the upper end of the lever pivotally attached to said slide rod and a weighted treadle bar extending transversely of the lower end of the post below the lower end of said lever and operatively engaged with the lower end of said lever,

a channel guide at the upper end of the post through which the rod is slidalole and anti-friction bearings in said guide for said rod and a dash-pot construction associated with the treadle bar for cushioning descending movements of the weighted end thereof.

6. In a racket stringing machine, wherein a racket supporting head is mounted upon the upper end of a tubular post, string tensioning means including a rod slidable transversely of the upper end of the post beneath the head, a string grip- .per adjustabiy mounted on one end of said rod whereby said gripper may engage a string section the same distance from a racket being strung to impart even tension to all sections of the racket string, a substantially vertically disposed lever pivoted between its upper and lower ends in the tubular post to the side wall thereof with the upper end of the lever pivotally attached to said slide rod and a weighted treadle bar extending transversely of the lower end of the post below the lower end of said lever and operatively engaged with the lower end of said lever.

EDMUNDO H. SERRANO. 

